1. Field of the Invention
The present invention pertains to a clamp assembly for gripping a length of pipe and providing a means for attaching said pipe to a lifting means such as, for example, a crane. More particularly, the present invention pertains to a clamp assembly for use in safely and efficiently guiding and threading a length of continuous tubing from a spool or reel into and out of an injector head. More particularly still, the present invention pertains to a clamp assembly that can remain attached to a length of continuous tubing to prevent said tubing from passing through a guide on a reel or coil.
2. Brief Description of the Prior Art
In servicing oil and gas wells, a continuous length of pipe, generally referred to as “coiled tubing”, can be used. Such coiled tubing generally comprises a length of continuous pipe wrapped on a spool, such that a desired length of tubing may be unspooled from said spool, passed through an injector head mounted on a well and injected into said well. After operations are completed, said coiled tubing can be retracted from the well and wound back on said spool.
During setup of a coiled tubing operation, a crane or other lifting device is frequently used to move the outer end of a length of continuous tubing from a spool to an injector, both of which can be positioned twenty feet or more above the ground or other support surface. In order to accomplish such transfer, it is generally necessary to connect said crane or other lifting means to said tubing at or near the outer end of said tubing. Once said crane or other lifting means is securely attached to said tubing, the end of the tubing can be lifted and laterally moved (and partially unspooled) to the intake of an injector head.
Once a well service operation is complete, the process is typically reversed. Coiled tubing is retracted from a well until the distal end of said tubing reaches the intake of an injector head. Thereafter, a crane or other lifting device is connected to said outer end of said tubing, and moved laterally to said spool from said injector head while the tubing is reeled back on to said spool.
When a length of coiled tubing is fully wrapped on a spool, the outer end of said tubing can pull through the wind guide of said spool assembly, thereby making said outer end difficult to access. Consequently, it is generally advantageous to provide a means to prevent an outer end of said coiled tubing from being pulled completely through said guide toward said spool, thereby becoming loose on the reel and difficult to access.
Conventional tubing clamps are typically connected to a length of coiled tubing to provide an attachment means for attaching a crane or other lifting apparatus to said tubing. Such conventional tubing clamps generally comprise a plurality of pad-eyes—typically two (2)—disposed on a top face of said tubing clamp. A crane or other lifting means can then be connected to said pad eyes using slings or other connection means.
Conventional tubing clamps are generally not easy to use or reliable in terms of gripping strength. Further, conventional tubing clamps typically require a double leg sling set in order to attach to said clamp; such double leg sling sets are less readily available than other sling sets, and can take longer to connect and disconnect than other attachment means.
Thus, there is a need for a tubing clamp having a single lifting eye member that can attach to a crane hook, thereby beneficially providing a significant improvement in safety of operation as well as efficiency.